A dead cell in the battery itself will cause it to drain overnight. The battery must be replaced if it has a dead cell. Also any light that is on will cause this. Brake, dome, under hood, trunk, glove box, etc. A relay that is stuck closed is another cause.
a battery
dead battery , poor cable connection to battery
battery no longer can store a electrical charge, a charging system failure, a parasitic draw,
A short in electrical system within the battery where two cells short together.
i think you are having problem with your alternator its not charging your battery
If the ignition isn't firing then you're looking at an electrical problem: Bad spark plugs, distributor, cables or battery. If you're frequently draining your battery and needing jump starts, the alternator could be failing as well.
The main cause of battery drains is a bad electrical system. The electrical system is normally powered by the alternator and once the alternator goes bad the battery has a hard time holding a charge,
A car battery in any car would drain due to a short in the electrical system.
My understanding is that you are hearing the starter "click" but it does not engage. If that is correct your answer is: Typically either 1. the battery isn't fully charged (either a problem with the charging system, something is running the battery down or the alternator isn't charging properly) 2. a poor electrical connection somewhere between the starter and the battery or 3. a problem with the starter or solenoid.
Overcharging. Check your electrical system to see if the alternator is overcharging the battery. It can also be the battery is defective and needs replacing.
The amp light on a 1964 Buick Riviera typically indicates a problem with the electrical charging system. Common causes include a malfunctioning alternator or generator, a dead battery, or a fault in the wiring or connections. If the amp light comes on, it suggests that the vehicle is not generating enough electrical power to meet its demands, which can lead to battery drain and other electrical issues. It's advisable to check the charging system components for any faults or failures.
The battery light usually comes on if there is a charging system problem Either battery or alternator are the usual causes.